Lubricious extruded medical tubing

ABSTRACT

A medical tube having improved lubricity is disclosed. The medical tube is produced by extruding a polymer material blended with a lubricity enhancing additive through a resilient die. The polymer material can be medical-grade high-density polyethylene, and the lubricity enhancing additive can be a silicone-based or alloy-based material. The medical tube can include one or more internal elongated protuberances so as to reduce the internal surface area of the medical tube available to generate friction on a guide wire inserted or withdrawn through the medical tube.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/670,905, filed Aug. 7, 2017, now allowed, which is a continuation ofU.S. patent application Ser. No. 13/722,704, filed Dec. 20, 2012, nowU.S. Pat. No. 9,744,332, which claims the benefit of and priority toU.S. Provisional Application Nos. 61/656,302, filed Jun. 6, 2012, and61/587,859, filed Jan. 18, 2012, each of which is hereby incorporated byreference herein in its entirety.

FIELD OF INVENTION

The present invention generally relates to extruded tubing useful formedical applications, such as protective dispenser coils for medicalcatheters or medical guide wires. More specifically, the presentinvention is directed to an extruded medical tubing formed from ablended thermoplastic material with an interior surface having enhancedlubricity to allow for efficient insertion and withdrawal of medicaldevices such as guide wires and/or catheters.

BACKGROUND

Medical tubing is used to house surgical medical devices during shippingand handling. Such medical tubing may be referred to as a protectivedispenser tubing. Examples of medical devices distributed in protectivedispenser tubing include guide wires and catheters for cardiovascularsurgical interventions. The dispenser tubing is desirably coiled toallow for efficient packaging and handling. The dispenser tubing isgenerally packaged so as to maintain sterility of the medical devicessituated within the tubing as well as prevent any damage or marring tosensitive instrumentation, such as delivery devices for cardiovascularsurgery, e.g., stents, balloons, etc. Prior to shipment, such dispensertubing is loaded with the medical devices in a sterile environment.During a surgical procedure, the medical devices are withdrawn from thedispenser tubing just prior to insertion into a patient's vascularsystem by medical personnel.

Protective dispenser tubing is generally formed by extruding an organicresin, such as polyethylene, polyolefin, polypropylene, etc, through adie. The temperature and/or pressure applied to the material iscontrolled to achieve a desired viscosity to allow for the material tobe extruded through the die while achieving results that satisfy desiredtolerances. Once the material is extruded through the die to take atubular shape, the resulting tubing is allowed to cool and cut todesired lengths.

The dispenser tubing is desirably formed from a material exhibitingsufficient resistance to crushing forces to substantially maintain thedimensions of an internal passageway of the tubing under ordinaryexternal forces encountered during shipping and handling. The tubingalso desirably exhibits sufficient flexibility to allow the tubing to becoiled and thereby allow for more compact and efficient packaging of themedical devices housed within. Systems and devices for retainingdispenser tubing in a coiled configuration during shipping and handlingoperations is described, for example, by U.S. Pat. No. 6,405,414, thecontents of which are incorporated entirely herein by reference.

Some applications of guide wires, stents, and other vascular medicaldevices housed within dispenser tubing, to provide cardiovascularinterventions during a surgical procedure are described in U.S. Pat. No.6,464,683, the contents of which are incorporated entirely herein byreference. In some applications, the medical device is introduced intothe patient's vascular system by an introducing catheter “introducer”incorporating a cannula to puncture the patient's skin, at which pointthe guide wire, catheter, or other medical device can be directed, e.g.,pushed, to the desired treatment region within the patient's vascularsystem. An example of a guide wire introducer is described U.S. Pat. No.5,282,479, the contents of which are incorporated entirely herein byreference.

SUMMARY

Dispenser tubing is regularly loaded with medical devices, such as guidewires, and then the medical device is extracted by a medicalprofessional during a surgical treatment using the medical device. Someguide wires can be as long as 180 inches, and loading such a lengthyguide wire can result in snags, stoppages, and kinks in the guide wire.In addition to the potential for damaging the guide wire, such acumbersome loading procedure is costly and unmanageable in a largeoperation. There is therefore a need for a dispenser tube with enhancedlubricity along its internal surface such that medical devices, such asguide wires can be readily loaded and unloaded without problems typicalof conventional dispenser tubes.

The magnitude of the motion-opposing frictional forces generated betweenthe dispenser tube and a guide wire housed therein is proportional to,among other things, the coefficient of friction between the contactingsurfaces of the two and the cumulative area the guide wire contacts anyportion of the dispenser tube. The present disclosure provides at leasttwo methods for improving the lubricity of a dispenser tube, which canbe employed separately, or together to benefit from a combined effect.By providing elongated protuberances along an internal surface of adispenser tube, the cumulative contact area between the guide wire andthe dispenser tube is reduced, relative to a dispenser tube with asmooth, non-striated interior surface. Thus, the amount ofmotion-opposing friction between the guide wire and the striateddispenser tube is reduced by reason of the reduced contact area.Additionally or alternatively, the polymer matrix forming the extrudeddispenser tube can be blended with a lubricity enhanced additive, suchas an alloy-based or silicon-based additive. As described herein, thelubricity enhanced additive reduces the coefficient of friction of theinternal surface of the dispenser tube and thereby reduces frictionforces between a dispenser tube so formed and a guide wire.

Some embodiments of the present disclosure provide dispenser tubingextruded from a poly/alloy or poly/silicone blended material mixedaccording to the present disclosure and having a smooth (i.e.,non-striated) interior surface. Some embodiments of the presentdisclosure provide dispenser tubing extruded from a thermoplasticmaterial, such as medical grade high density polyethylene and having astriated interior surface. Some embodiments of the present disclosureprovide dispenser tubing extruded from a poly/alloy or poly/siliconeblended material mixed according to the present disclosure and having astriated interior surface.

Some embodiments of the present disclosure include a lubricous medicaltube formed from a blended material including organic polymer resin, anda lubricity enhancing additive blended with the organic polymer resin toform a blended material. The blended material can be disposed in asubstantially tubular configuration bounded by an inner surface and anouter surface encompassing the inner surface. In some embodiments, theorganic polymer resin can include medical-grade high-densitypolyethylene. In some embodiments, the lubricity enhancing additive isselected from a silicon-based material or an alloy-based material. Insome embodiments, the lubricity enhancing additive can includeFranklinite. In some embodiments, the lubricity enhancing additive isblended with the organic polymer resin at a concentration of less than10%, or of less than 5%, or of approximately 3%, or of approximately 2%,or of approximately 1%.

Some embodiments of the present disclosure provide for the inner surfaceof the medical tube to be formed with a plurality of elongatedprotuberances arranged to extend substantially parallel to a lengthdimension of the medical tube. In some embodiments, the plurality ofelongated protuberances are configured such that each of theprotuberances is characterized by a raised apex, the raised apex beingcloser to an axis of substantial cylindrical symmetry of the medicaltube than a depressed region located between adjacent ones of theplurality of elongated protuberances. In some embodiments, the pluralityof elongated protuberances are configured such that a medical guide wireinserted in the medical tube contacts at least a portion of one or moreof the plurality of elongated protuberances, including the raisedapexes, without contacting at least a portion of the inner surfacebetween adjacent ones of the plurality of protuberances. In someembodiments, the plurality of elongated protuberances are substantiallyevenly spaced about the interior surface of the medical tube. In someembodiments, the inner surface is sufficiently lubricious to allowinsertion or withdrawal of a guide wire into the lubricious medical tubewhile the lubricious medical tube remains in a coiled configuration.

BRIEF DESCRIPTION OF THE DRAWINGS

Non-limiting embodiments of the present invention will be described byway of example with reference to the accompanying figures, which areschematic and are not intended to be drawn to scale. In the figures,each identical or nearly identical component illustrated is typicallyrepresented by a single numeral. For purposes of clarity, not everycomponent is labeled in every figure, nor is every component of eachembodiment of the invention shown where illustration is not necessary toallow those of ordinary skill in the art to understand the invention. Inthe figures:

FIG. 1 shows a lubricious dispenser tube for housing a medical devicesuch as a guide wire or a catheter.

FIG. 2A is an aspect view of the dispenser tube showing an end of thedispenser tube in an open state, i.e., with no guide wire housed withinthe dispenser tube.

FIG. 2B is an aspect view of the dispenser tube 10 shown in FIG. 2A,where the dispenser tube is housing a guide wire.

FIG. 3 is a flowchart illustrating an example procedure for preparingthe lubricious dispenser tube shown and described in connection withFIGS. 1 and 2.

FIG. 4A is a cross-sectional view of a striated dispenser tube having aplurality of raised protuberances 119 along an internal surface of thedispenser tube.

FIG. 4B provides a magnified view of a bottom portion of thecross-sectional view shown in FIG. 4A.

FIG. 4C is an aspect view of the striated dispenser tube showing an openend of the striated dispenser tube with the elongated protrusionsvisible on the interior surface.

FIG. 5A is an aspect view of the striated dispenser tube similar to FIG.4C, but where the striated dispenser tube is housing the guide wire.

FIG. 5B illustrates a cross-sectional view of the striated dispensertube housing the guide wire shown in FIG. 5A.

FIG. 6A is a cross-sectional view of an example of a striated dispensertube having 65 circumferentially arranged elongated protuberances.

FIG. 6B is a cross-sectional view of an example of a striated dispensertube having 90 circumferentially arranged elongated protuberances.

FIG. 7 is a top view of an extrusion die used to produce a striateddispenser tube in accordance with the present disclosure.

FIG. 8 is a flowchart illustrating an example procedure for preparingthe lubricious dispenser tube shown and described in connection withFIGS. 4 through 5.

DETAILED DESCRIPTION

FIG. 1 shows a lubricious dispenser tube 10 for housing a medical devicesuch as a guide wire or a catheter. For expediency in the remainder ofthis disclosure, unless specifically stated otherwise, the variouslubricious dispenser tubes disclosed herein will be described withreference to housing a guide wire. However, it is specifically notedthat the dispenser tubes described herein can also house catheters andother medical devices suitable for being dispensed from a sterile coiledtube to maintain sterility and integrity of the medical device duringtransport. The lubricious dispenser tube 10 is securely held in a coiledposition by the clips 12, 14. The clips can be extruded unitary plasticclips having a plurality of adjacent sockets for griping the tube 10 andsecuring it to another portion of the tube 10 so as to coil thedispensing tube 10 in a spiral configuration. The clips can have, forexample, two sockets (12) or three sockets (14). An example of asuitable clip for securing a dispensing tube in a spiral woundconfiguration is described in U.S. Pat. No. 6,405,414, the contents ofwhich are incorporated herein in its entirety. Thus, a guide wire housedwithin the dispenser tube 10 can be compactly and efficiently handled tobe delivered from a sterile production and packaging environment to asurgical suite or operating room without sacrificing the structuralintegrity or sterility of the guide wire housed.

FIG. 2A is an aspect view of the dispenser tube 10 showing an end 20 ofthe dispenser tube 10 in an open state, i.e., with no guide wire housedwithin the dispenser tube 10. The dispenser tube 10 has an exteriorcylindrical (“tubular”) surface 16 and an interior cylindrical surface18. The exterior surface 16 is substantially equidistant from a centralaxis 2 defining an axis of substantial cylindrical symmetry of thedispenser tube 10. The interior surface 18 is located radially interiorto the exterior surface 16, with respect to the central axis 2, and isalso substantially equidistant from the central axis 2. The dispensertube 10 can be formed by an extrusion process to extrude materialbetween two surfaces of a die corresponding to the interior and exteriorsurfaces 16, 18 such that the extruded material is disposed between theinterior and exterior surfaces 16, 18.

The interior surface 18 defines a passageway, i.e., interior channel orlumen, of the dispenser tube for housing medical guide wires and forreceiving guide wires as they are loaded (during packaging) and unloaded(in connection with a surgical procedure). As shown in FIG. 2B, a guidewire 30 is inserted and/or withdrawn from the dispenser tube 10. Theguide wire 30 can be formed of materials including stainless steel,nitinol, or other materials used for guide wires in angioplasty, stent,and other cardiovascular surgical procedures. The guide wire 30 has anend 32 and an external side wall 34, which can be a substantiallycylindrical wall sized to fit within the internal surface 18 of thedispenser tube 10 so as to allow the guide wire 30 to be housed withinthe dispenser tube 10. As indicated by the directional arrow 36, theguide wire 30 is inserted and withdrawn from the dispenser tube vialongitudinal forces, e.g., pushing or pulling forces, exerted on theguide wire 30 with respect to the dispenser tube 10. During insertion orwithdrawal of the guide wire 30 to or from the dispenser tube 10, theexternal side wall 34 contacts the interior surface 18 of the dispensertube 10, which contact results in motion-opposing frictional forcesbetween the interior surface 18 of the dispenser tube 10 and theexternal side wall 34 of the guide wire 30.

According to some embodiments of the present disclosure, the extrudedmaterial forming the dispenser tube 10 is a material that includes anorganic resin as a matrix material and a lubricity enhancing additiveblended with the resin. In some embodiments the resin can be athermoplastic polymer-based material, such as medical grade high densitypolyethylene. Some embodiments can also incorporate polyolefin,polypropylene, and the like as a matrix material or blended ingredient.The lubricity enhancing additive can be a silicon-based material, suchas siloxane and/or an ultra-high molecular weight silicone material. Insome embodiments, the lubricity enhancing additive can additionally oralternatively include an alloy, such as Franklinite,(Zn,Mn²⁺,Fe²⁺)(Fe³⁺,Mn³⁺)₂O₄, or another alloy having particles withsurface hardness greater than that of the surrounding poly matrix.

In some embodiments, the lubricity enhancing additive can additionallyor alternatively include materials with a melt flow index (MFI) betweenapproximately 7 and approximately 13 grams per 10 minutes, under thestandards at ASTM D 1238 and/or ISO 1133. In some embodiments, thelubricity enhancing additive can additionally or alternatively includematerials with a bulk density between approximately 30 and approximately35 pounds per cubic foot, under the standards at ASTM D 1895-67(B). Insome embodiments, the lubricity enhancing additive can additionally oralternatively include materials with a moisture content less thanapproximately 0.5% as determined by an electronic moisture analyser, forexample. Thus, the lubricity enhancing additive can have a molecularstructure, molecular weight, and/or grain size, etc. such that theadditive material has an MFI between approximately 7 and approximately13 gms/10 mins; a bulk density between approximately 30 andapproximately 35 lbs/ft³; and/or a moisture content less thanapproximately 0.5%. In some examples, the lubricity enhancing additivecan be a polymeric material, alloy-based material, and/or siliconematerial that is suitable for food and/or medical applications, such asadditives sanctioned by the F.D.A. for use under conditions subject tocontact with food and/or medical materials. Additionally oralternatively, the lubricity enhancing additive (and the resultingpolymeric blended material) can be substantially thermally stable atextrusion processing temperatures, such as, for example, temperaturesbetween approximately 350 degrees and approximately 450 degrees.Furthermore, the lubricity enhancing additive can be a combination of analloy-based material (such as a material including Franklinite) and apolymeric material (such as a material with the properties describedabove).

In some embodiments, the lubricity enhancing additive, such as thealloy, is not readily soluble within the melted polymer matrix blend andas a result migrates preferentially toward the tube surfaces during theextrusion. Such an extruded dispenser tube can be at least partiallysurrounded by a film or thin layer of an enhanced amount of lubricityenhancing additive. The lubricity enhancing additive, such as, forexample, an alloy material, a polymeric material, a silicone material,or a combination of such materials, is blended with the matrix materialat a concentration in the range of 0.5% to 10%. In some embodiments thelubricity enhancing additive can be blended with the matrix material ata concentration of approximately 2%. In some embodiments the lubricityenhancing additive can be blended with the matrix material at aconcentration of approximately 3%. In some other examples, the lubricityenhancing additive can optionally be blended with the matrix at aconcentration in the range of 25.8%±2%.

The resulting blended material is heated so as to provide a desiredviscosity and/or solubility sufficient for extrusion processing and theblended material (e.g., the poly/alloy blended material) is directedthrough a die to form the dispenser tube 10 described above inconnection with FIGS. 1-2. As a result of the presence of the blendedsilicone-based or alloy-based lubricity enhancing additive, thelubricious dispenser tube 10 exhibits a decreased coefficient offriction between the internal surface 18 of the dispenser tube 10 andthe external side wall 34 of the guide wire 30. The enhanced lubricitymay be due to the increased presence of hard surface particles, near theinterior surface 18, which are relatively less likely than conventionalpolymer matrix material particles to microscopically deform or spread inresponse to microscopic physical contact from the guide wire 30, whichmicroscopic deforming and/or spreading generates a motion-opposingfrictional force.

The resulting lubricious dispenser tube 10 is less likely to grab, kink,or cause stoppage of the guide wire 30 within the dispenser tube 10before fully inserted. Furthermore, by increasing the lubricity, i.e.,decreasing the coefficient of friction of the interior surface 18, theguide wire 30 is loaded into the dispenser tube 10 with less resistance,and can be loaded while the dispenser tube 10 remains in a coiled(“spiral wound”) configuration, such as the coiled configurationillustrated in FIG. 1. Even where it may have been possible to load theguide wire while the dispenser tube 10 was coiled, the dispenser tube 10can now be coiled more tightly than previously possible while loadingthe guide wire 30. Additionally or alternatively, the dispenser tube 30can be more tightly wound than previously thought possible prior toshipping, because the lubricious interior surface 18 allows the guidewire 30 to be withdrawn from a coiled dispenser tube 10 that is coiledmore tightly (e.g., at a smaller radius) than previously thoughtpossible. As a result, the lubricious dispenser tube 10 disclosed hereinallows for more compact and efficient packaging of guide wires thanpreviously available because the dispenser tube 10 can now be moretightly wound so as to take up a smaller area than previously thoughtpossible.

FIG. 3 is a flowchart illustrating an example procedure for preparingthe lubricious dispenser tube 10 shown and described in connection withFIGS. 1 and 2. A lubricity enhancing additive is blended with an organicpolymer resin (polymer matrix material) to create a blended material(40). The temperature and/or pressure of the blended material iscontrolled according to typical extrusion processing so as to achieve aviscosity of the blended material suitable for being extruded (42). Theblended material is then extruded through a resilient die to form atubular structure having substantially cylindrically symmetric interiorand exterior surfaces bounding the tubular structure formed of theblended material (44). The extruded tubular structure is allowed to cooluntil it achieves a viscosity suitable for further processing, (46).

Further aspects of the present disclosure provide for enhancing thelubricity of dispenser tubing by providing a plurality of elongatedraised protuberances along the interior surface of the tube. A guidewire inserted therein makes contact predominantly with the raisedprotuberances, rather than the entire interior surface and therebyavoids surface friction from at least some portions of the interiorsurface that are not raised.

FIG. 4A is a cross-sectional view of a striated dispenser tube 110having a plurality of raised protuberances 119 along an internal surface118 of the dispenser tube 110. FIG. 4B provides a magnified view of abottom portion of the cross-sectional view shown in FIG. 4A. Thecross-sectional view in FIGS. 4A and 4B is taken along a planesubstantially perpendicular to the imaginary axis 102 extending throughthe center of the striated dispenser tube 110. The plurality of raisedprotuberances 119 may be referred to alternatively as internal ribs,ridges, striations, etc. The raised protuberances generally extend alonga direction substantially parallel to the imaginary axis 102.

It is specifically noted that in FIGS. 4A and 4B, there are a pluralityof circumferentially evenly spaced protuberances 119, but only one ortwo such protuberances are explicitly labelled for ease of illustration.Similarly, between each of the plurality of protuberances 119, thereexists a plurality of elongated depressions 117, which not eachseparately labelled in the drawings for each of illustration. It is alsonoted that the striated dispenser tube 110 is generally considered to besubstantially cylindrically symmetric about the imaginary axis 102, withthe interior surface 118, which is situated generally between a firstradius R1 and a second radius R2 from the imaginary axis 102. Bycomparison, the exterior surface 116 of the striated dispenser tube 110is substantially equidistant from the imaginary axis 102 at a distanceR3, (e.g., the exterior surface 116 is substantially cylindricallysymmetric with respect to the imaginary axis 102).

Each of the raised protuberances 119 can be generally circumferentiallyevenly spaced about the interior surface 118, and can be situated withadjacent protuberances 119 separated by depressions 117. An exemplarygeometric arrangement of the protuberances 119 and the depressions 117is described in connection with the close-in view in FIG. 4B. Generally,the depressions 117 include at least a portion of the interior wall 118that is distant from the imaginary axis 102 by the second radius R2, andthe protuberances 119 include at least a portion that is distant fromthe imaginary axis 102 by the first radius R1. Adjacent ones of theprotuberances are separated by a distance D1, along the circumference ofthe interior surface. To name one example, the separation distance D1can be 0.0088 inches, but the separation distance can be other numbersas well. The value of the first radius R1 is generally selected to allowpassage of the guide wire 30 being housed within the striated dispensertubing 110. The dimension of the second radius R2 is selected such thatthe difference between the first and second radii, which defines themaximal height of the protuberance 119 with respect to the depressions117 is not substantially different from the separation distance betweenadjacent protuberances. For example, the value of R2 can be selectedaccording to a formula, such as, e.g., R2−R1<k D1, wherein k is a smallnumber, such as a number less than 5 or less than 3. If the height ofthe protrusion, i.e., R2−R1, is allowed to substantially exceed theseparation distance, the protrusions become substantially taller thanthey are wide, and there is some risk that they may sacrifice structuralintegrity, for example, the protrusions 119 may wobble or otherwise beundesirably displaceable in response to a guide wire being loaded intothe striated dispenser tube 110. In addition, the second radius R2 isselected to maintain a sufficient thickness of the wall 120,characterized generally by the difference between the third and secondradii, i.e., R3−R2.

In addition, the number of protrusions 119 circumferentially locatedabout the interior surface 118 can be adjusted for different sizes ofthe striated dispenser tube 118. In one example, a relationship may beestablished between one or more of the first radius (i.e., radius of theguide wire to be loaded), the second radius, and the separation distanceD1. Such a relationship may desirably ensure that there remain asufficient number of protrusions to allow the guide wire 30 to be loadedwithin the striated dispenser tubing by having the external side wall 34of the guide wire 30 slide on portions adjacent ones of the plurality ofprotuberances 119 without contacting the depressions 117 between theprotuberances 119.

To further illustrate the geometric arrangement of the protrusions 119and the depressions 117, the dimensions of an example one of theprotuberances 119 are described in connection with the enhanced viewshown in FIG. 4B. The protuberance 119 is characterized by an apex 122which appears in the cross section as the point on the protuberance 119nearest the imaginary axis 102. For example, the apex 122 can beseparated from the imaginary axis 102 by the first radius R1.Accordingly, the apexes 122 of the plurality of protuberances 119 definelines on the interior surface 118 that are most proximate to theimaginary axis 102. The apex 122 can be the crest of a pronounced region124 having a curvature generally away from the imaginary axis 102. Forexample, the pronounced region 124 can be characterized by a radius ofcurvature with an axis internal to the wall 120 of the striateddispenser tube 110. The radius of curvature of the pronounced region canbe the radius r1 illustrated in FIG. 4B. The pronounced region 124continues to an inflection point 125, which is disposed on both sides ofthe pronounced region 124 at positions approximately equidistant fromthe apex 122. Upon crossing the inflection point 125, travelling fromthe pronounced region 124, the depressed region 126 is encountered.Thus, the inflection point 125 indicates a location of change ofcurvature. The depressed region 126 is characterized by the interiorwall 118 curving generally toward the imaginary axis 102. For example,the depressed region 126 can be characterized by a radius of curvaturewith an axis inside the cavity defined by the interior surface 118(e.g., not within the wall 120, but rather between the interior surface118 and the imaginary axis 102). The radius of curvature of thedepressed region 126 can be the radius r2 illustrated in FIG. 4B. Thedepressed region 126 includes a low point 128, which is the most distantpoint from the imaginary axis 102 within the depressed region 126, e.g.,the distance given by the second radius R2.

FIG. 4C is an aspect view of the striated dispenser tube 110 showing anopen end of the striated dispenser tube 110 with the elongatedprotrusions 119 visible on the interior surface 118. The striations areoriented substantially perpendicularly to the imaginary axis 102.

FIG. 5A is an aspect view of the striated dispenser tube 110 similar toFIG. 4C, but where the striated dispenser tube 110 is housing the guidewire 30. Similar to FIG. 2B, the directional arrow 36 illustrates thedirection of insertion and/or withdrawal of the guide wire 30 withrespect to the striated dispenser tube 110. FIG. 5B illustrates across-sectional view of the striated dispenser tube 110 housing theguide wire 30 shown in FIG. 5A.

As shown in FIGS. 5A and 5B, the guide wire 30 does not maintain acontinuous circumferential connection to the interior surface 118 of thestriated dispenser tube 110. Rather, the guide wire 30 slides alongraised portions (e.g., portions including the apexes 122) of theelongated protuberances 119 without contacting the at least a portion ofthe interior surface 118 between adjacent ones of the elongatedprotuberances 119 (e.g., portions including the low points 128). Thus,the external side wall 34 of the guide wire 30 contacts only a portionof the interior surface 118 while being loaded or withdrawn from thestriated dispenser tube 110.

FIG. 6A is a cross-sectional view of an example of a striated dispensertube 210 having 65 circumferentially arranged elongated protuberances.The individual elongated protuberances are similar to those described inconnection with the striated dispenser tube 110 of FIGS. 4 through 5,but there are more such protuberances. In one example implementation ofthe striated dispenser tube 210, the circumferential distance betweenadjacent protuberances is 0.0088 inches, the outer diameter is 0.225inches and the inner diameter is 0.175 inches.

FIG. 6B is a cross-sectional view of an example of a striated dispensertube 310 having 90 circumferentially arranged elongated protuberances.In one example implementation of the striated dispenser tube 310, thecircumferential distance between adjacent protuberances is 0.0088inches, the outer diameter is 0.300 inches and the inner diameter is0.250 inches.

Exemplary dimensional values of dispenser tubes produced according tothe present disclosure are provided below in Table 1.

TABLE 1 Exemplary dimensional values of lubricious extruded dispensertubes according to embodiments of the present disclosure. Outer InnerCircumferential Number of Diameter Diameter Distance Protuberances (2R3) (2 R1) Between Adjacent About the [inches] [inches] Protuberances[inches] Circumference 0.152 0.100 0.0088 28 ± 2 0.225 0.175 0.0088 65 ±2 0.225 0.185 0.0088 68 ± 2 0.300 0.250 0.0088 90 ± 2

FIG. 7 is a top view of an extrusion die 700 used to produce a striateddispenser tube in accordance with the present disclosure. The extrusiondie is constructed from a resilient material such as conventionally usedin extrusion processing. The extrusion die can be constructed to beresilient to aspects encountered during extrusion processing, such assolvents, coolants, high pressure, high temperatures, etc. As shown inFIG. 7, the extrusion die 700 includes a removed central region and hasa generally circular shape. The circumference of the extrusion die issurrounded by protruding ribs separated by intended spaces, whichcombine to define a striated interior surface of a dispenser tubingextruded via the extrusion die 700. The protruding ribs are generallyterminated by a rounded feature. The protruding ribs are rounded with aradius of curvature having an axis interior to the extrusion die.Adjacent ones of the protruding ribs are separated by indented spacesthat are also rounded, but with a radius of curvature having an axisexternal the extrusion die. As will be understood, during an extrusionprocess using the extrusion die 700, extruded material along and throughthe indented spaces between the protruding ribs become raised ridges,such as the elongated protuberances 119 described in connection with thestriated dispenser tube 110 of FIGS. 4 and 5. Similarly, materialextruded along the protruding ribs become intended valleys, between theraised ridges, such as the depressions 117 described in connection withthe striated dispenser tube 110 of FIGS. 4 and 5.

FIG. 8 is a flowchart illustrating an example procedure for preparingthe lubricious dispenser tube 110 shown and described in connection withFIGS. 4 through 5 (or the lubricious dispenser tubes 210, 310 describedin connection with FIGS. 6A and 6B). A lubricity enhancing additive isblended with an organic polymer resin (polymer matrix material) tocreate a blended material (40). The temperature and/or pressure of theblended material is controlled according to typical extrusion processingso as to achieve a viscosity of the blended material suitable for beingextruded (42). The blended material is then extruded through a resilientdie to form a tubular structure having a substantially cylindricallysymmetric exterior surface and an interior surface having a plurality ofelongated protuberances bounding the tubular structure formed of theblended material (45). The extruded tubular structure is allowed to cooluntil it achieves a viscosity suitable for further processing, (46).

The magnitude of the motion-opposing frictional forces generated betweenthe striated dispenser tube 110 and the guide wire 30 is proportionalto, among other things, the coefficient of friction between thecontacting surfaces and the cumulative area where the external side wall34 of the guide wire 30 contacts any portion of the interior surface110. Accordingly, by providing the disclosed elongated protuberances 119to thereby reduce the contact area between the guide wire 30 and thestriated dispenser tube 110, relative to a dispenser tube with a smooth,non-striated interior surface, the amount of motion-opposing frictionbetween the guide wire 30 and the striated dispenser tube 110 isreduced. Additionally or alternatively, the polymer matrix blended witha lubricity enhancing additive, such as an alloy-based or silicon-basedadditive, provides a reduced coefficient of friction between a dispensertube 10, 110, 210, 310 formed from the blended material and the guidewire 30.

Some embodiments of the present disclosure provide dispenser tubingextruded from a poly/alloy or poly/silicone blended material mixedaccording to the present disclosure and having a smooth (i.e.,non-striated) interior surface. Some embodiments of the presentdisclosure provide dispenser tubing extruded from a thermoplasticmaterial, such as medical grade high density polyethylene and having astriated interior surface. Some embodiments of the present disclosureprovide dispenser tubing extruded from a poly/alloy or poly/siliconeblended material mixed according to the present disclosure and having astriated interior surface.

While there has been shown and described in some embodiments of anebulizer assembly in accordance with the invention, it will beappreciated that many changes and modifications can be made thereinwithout, however, departing from the essential spirit thereof. Thus, theinvention is not limited to the particular embodiments disclosed herein,for it can be realized that various size and/or shapes of the tubularhousing and/or nebulizer can be used for the purposes of the invention.The terminology used herein is for the purpose of describing particularembodiments only, and is not intended to limit the scope of the presentinvention, which is defined solely by the claims.

The singular terms “a,” “an,” and “the” include plural referents unlesscontext clearly indicates otherwise. Similarly, the word “or” isintended to include “and” unless the context clearly indicatesotherwise.

Although methods and materials similar or equivalent to those describedherein can be used in the practice or testing of this disclosure,suitable methods and materials are described below. The term “comprises”means “includes.” The abbreviation, “e.g.” is derived from the Latinexempli gratia, and is used herein to indicate a non-limiting example.Thus, the abbreviation “e.g.” is synonymous with the term “for example.”

All numbers expressing quantities used herein should be understood asmodified in all instances by the term “about.” The term “about” whenused in connection with percentages may mean±1%.

In the claims, as well as in the specification above, all transitionalphrases such as “comprising,” “including,” “having,” and “containing,”are to be understood to be open-ended, i.e., to mean including but notlimited to. Only the transitional phrases “consisting of” and“consisting essentially of” shall be closed or semi-closed transitionalphrases, respectively, as set forth in the United States Patent OfficeManual of Patent Examining Procedures, Section 2111.03.

Alternative Implementations

Alternative Implementation 1. A lubricous medical tube formed from ablended material including: organic polymer resin, and a lubricityenhancing additive blended with the organic polymer resin to form ablended material; and wherein the blended material is disposed in asubstantially tubular configuration bounded by an inner surface and anouter surface encompassing the inner surface.

Alternative Implementation 2. The lubricious medical tube of alternativeimplementation 1, wherein the organic polymer resin includes medicalgrade high-density polyethylene.

Alternative Implementation 3. The lubricious medical tube of alternativeimplementation 1 to 2, wherein the lubricity enhancing additive isselected from a silicon-based material or an alloy-based material.

Alternative Implementation 4. The lubricious medical tube of any one ofalternative implementations 1 to 3, wherein the lubricity enhancingadditive includes Franklinite.

Alternative Implementation 5. The lubricious medical tube of any one ofalternative implementations 1 to 4, wherein the lubricity enhancingadditive is blended with the organic polymer resin at a concentration ofless than 10%.

Alternative Implementation 6. The lubricious medical tube of any one ofalternative implementations 1 to 5 wherein the lubricity enhancingadditive is blended with the organic polymer resin at a concentration ofless than 5%.

Alternative Implementation 7. The lubricious medical tube of any one ofalternative implementations 1 to 6, wherein the lubricity enhancingadditive is blended with the organic polymer resin at a concentration ofapproximately 3%.

Alternative Implementation 8. The lubricious medical tube of any one ofalternative implementations 1 to 6, wherein the lubricity enhancingadditive is blended with the organic polymer resin at a concentration ofapproximately 2%.

Alternative Implementation 9. The lubricious medical tube of any one ofalternative implementations 1 to 6, wherein the lubricity enhancingadditive is blended with the organic polymer resin at a concentration ofapproximately 1%.

Alternative Implementation 10. The lubricious medical tube of any one ofalternative implementations 1 to 9, wherein the inner surface of themedical tube is formed with a plurality of elongated protuberancesarranged to extend substantially parallel to a length dimension of themedical tube.

Alternative Implementation 11. The lubricious medical tube ofalternative implementation 10, wherein the plurality of elongatedprotuberances are configured such that each of the protuberances ischaracterized by a raised apex, the raised apex being closer to an axisof substantial cylindrical symmetry of the medical tube than a depressedregion located between adjacent ones of the plurality of elongatedprotuberances.

Alternative Implementation 12. The lubricious medical tube ofalternative implementation 10 or 11, wherein the plurality of elongatedprotuberances are configured such that a medical guide wire inserted inthe medical tube contacts at least a portion of one or more of theplurality of elongated protuberances, including the raised apexes,without contacting at least a portion of the inner surface betweenadjacent ones of the plurality of protuberances.

Alternative Implementation 13. The lubricious medical tube of any one ofalternative implementations 10 to 12, wherein the plurality of elongatedprotuberances are substantially evenly spaced about the interior surfaceof the medical tube.

Alternative Implementation 14. The lubricious medical tube of any one ofalternative implementations 1 to 13, wherein the inner surface issufficiently lubricious to allow insertion or withdrawal of a guide wireinto the lubricious medical tube while the lubricious medical tube isheld in a coiled configuration.

Alternative Implementation 15. A method of preparing a medical tubecomprising: blending an organic polymer resin with a lubricity enhancingadditive to create a blended material; controlling the temperature orpressure of the blended material so as to achieve a viscosity of theblended material suitable for being extruded; extruding the blendedmaterial through a resilient die to form a tubular structure suitablefor use as a dispenser tube for a medical device housed therein; andallowing the extruded tubular structure to cool until it achieves astate suitable for further processing.

Alternative Implementation 16. The method of alternative implementation15, wherein the extruding is carried out to create an extruded a tubularstructure having a substantially cylindrically symmetric exteriorsurface and an interior surface having a plurality of elongatedprotuberances bounding the tubular structure formed of the blendedmaterial.

Alternative Implementation 17. The method of alternative implementation15 or 16, wherein the method is carried out so as to produce the medicaltube disclosed in any one of alternative implementations 1 to 14.

Alternative Implementation 18. A dispenser assembly comprising: alubricious medical tube formed from a mixture of an organic polymerresin blended with a lubricity enhancing additive, the lubriciousmedical tube configured such that the blended mixture is bounded betweenan inner surface and an external surface encompassing the inner surface,and a medical device housed within the lubricious medical tube.

Alternative Implementation 19. The dispenser assembly of alternativeimplementation 18, wherein the lubricious medical tube is a lubriciousmedical tube as disclosed in any one of alternative implementations 1 to14.

Alternative Implementation 20. The dispenser assembly of alternativeimplementation 18 or 19, further comprising one or more tubing clips tosecure the lubricious medical tube in a coiled configuration.

Alternative Implementation 21. The dispenser assembly of any one ofalternative implementations 18 to 20, wherein the medical device housedwithin the lubricious medical tube is a guide wire for use in acardiovascular surgical procedure.

Various changes and modifications to the disclosed embodiments, whichwill be apparent to those of skill in the art, may be made withoutdeparting from the spirit and scope of the present invention. Further,all patents and other publications identified are expressly incorporatedherein by reference for the purpose of describing and disclosing, forexample, the methodologies described in such publications that might beused in connection with the present invention. These publications areprovided solely for their disclosure prior to the filing date of thepresent application. Nothing in this regard should be construed as anadmission that the inventors are not entitled to antedate suchdisclosure by virtue of prior invention or for any other reason. Allstatements as to the date or representation as to the contents of thesedocuments is based on the information available to the applicants anddoes not constitute any admission as to the correctness of the dates orcontents of these documents.

What is claimed is:
 1. A medical tube formed from a blended material,comprising: organic polymer resin; and 0.5 percent to three percentlubricity enhancing additive blended with the organic polymer resin toform the blended material, wherein the lubricity enhancing additive isalloy-based, wherein the blended material is extruded into the medicaltube such that the medical tube has a substantially tubularconfiguration with an inner surface and an outer surface.
 2. The medicaltube of claim 1, wherein the blended material is at least aboutninety-five percent organic polymer resin.
 3. The medical tube of claim1, wherein the lubricity enhancing additive has a bulk density betweenabout thirty pounds per cubic foot and about thirty-five pounds percubic foot.
 4. The medical tube of claim 1, wherein the lubricityenhancing additive has a moisture content less than about one-half of apercent.
 5. The medical tube of claim 1, wherein the organic polymerresin is high-density polyethylene.
 6. The medical tube of claim 1,wherein the lubricity enhancing additive is Franklinite.
 7. The medicaltube of claim 1, wherein the inner surface of the medical tube is formedwith a plurality of elongated protuberances.
 8. The medical tube ofclaim 7, wherein the plurality of elongated protuberances is arrangedsuch that each of the plurality of elongated protuberances extendssubstantially parallel to a length dimension of the medical tube.
 9. Themedical tube of claim 1, wherein the inner surface of the medical tubeis sufficiently lubricious to allow insertion or withdrawal of a guidewire into the medical tube while the medical tube is in a substantiallycoiled configuration.
 10. The medical tube of claim 1, furthercomprising a guide wire positioned at least partially within the medicaltube.
 11. The medical tube of claim 1, wherein the inner surface of themedical tube is smooth.
 12. The medical tube of claim 1, wherein anouter diameter of the medical tube is between 0.152 inches and 0.300inches and an inner diameter of the medical tube is between 0.100 inchesand 0.250 inches.
 13. The medical tube of claim 1, wherein the lubricityenhancing additive has a melt flow index (MFI) between about seven gramsper ten minutes and thirteen grams per ten minutes, wherein thelubricity enhancing additive has a bulk density between about thirtypounds per cubic foot and about thirty-five pounds per cubic foot, andwherein the lubricity enhancing additive has a moisture content lessthan about one-half of a percent.
 14. A method of preparing a medicaltube comprising: blending an organic polymer resin with a lubricityenhancing additive to create a blended material, the blended materialincluding organic polymer resin and 0.5 percent to three percentlubricity enhancing additive, wherein the lubricity enhancing additiveis alloy-based; achieving a viscosity of the blended material suitablefor extrusion; and extruding the blended material through a die.
 15. Themethod of claim 14, wherein the achieving includes controlling thetemperature, pressure, or both of the blended material.
 16. The methodof claim 15, wherein the temperature is controlled to be betweenapproximately 350 degrees and approximately 450 degrees.
 17. The methodof claim 14, wherein the extruding the blended material through the dieincludes forming a substantially tubular structure.
 18. The method ofclaim 14, further comprising permitting the extruded blended material tocool.
 19. The method of claim 14, further comprising cutting theextruded blended material, thereby forming the medical tube.
 20. Themethod of claim 19, wherein the lubricity enhancing additive is siloxaneFranklinite.